Intelligence transmission system



sepf.3,1946. L. A. D ROSA 2,406,813

u INTELLIGENCE TRASMISSION 4SYSTEM Filed June 18, 1943 5I Sheets-Sheet 2INVENTOR. ou/s A. pfos/l Sept. 3, 1946. L. A. DE4 -RosA 2,406,813

INTELLIGENCE TRANSMISSION SYSTEM l IN VEN TOR. LOU/6 A. 11e-R054Armin/EY mitteil, such as a letter or numeral.

Patented Sept. 3, 1946 INTELLIGENCE TRANSMISSIN SYSTEM Louis de Rosa,West Brighton, Staten Island, N. Y., assignor to Federal Telephone andRadio ,v N. J., a corporation oi' Corporation, Newark DelawareApplication June 18, 1943, `Serial No. 491,287

(o1. `rise-3o) 10 Claims. .l

This invention relates to .improvements in intelligence transmissionsystems, and more particularly 4to systems in which intelligence istransmitted in the form Vof pulses, and lreceived and converted intovisual intelligence,

Systems have `been heretofore proposed in which intelligence in the formof pulses or a series of pulses is transmitted directly or Toy-carrierWave tc a receiver where such 4pulses vare converted into visualintelligenceeither by means of controlling the pattern on the screen ofa .cathode ray tube Yor `by impressions upon a moving tape. In `som-esystems ythe characterxto be transmitted is divided `up-` into severaltransverse bands such as ve for seven, of several groups of pulses each,the-number position oi pulses in each band fdeterm-ininglthe formationof the transmitted character. The 'pulses may be sent at -a commonfrequency, or, it iis sometimes y.ad-- vautageous to transmit each bandlof :pulses at different frequencies.

In all such systems the interval between pulses or sets of pulses is-determinative of the character to "be reproduced' at the receiver, andvarious means have been proposed to produce sets of such timed'pulses in.accordance with the characteristics Yof lthe intelligence to be trans-In prior systems it `been usual to ypra-form mechanical patterns which,through the 4use of lightresconsive -`tubes or similar 'glneans formseries of pulses `corresponding1to the letter to be transmitted, thepattern chosen being controlled by a keyboard Lor :similar means. Suchsystems and such means vare described, .for example, in the copendingapp-licationsfof 'Edmond M, Deloraine, S. N. 415,554 .filed October11941'ra-nd Edmond M. Deloraine, `et al., S. N; 469,056 iiled 'Decemberl5, 1942.

It is one of the objects ci theipresent invention to eliminate the .useoi mechanical devices mission system, :together with controllable meansfor startiugzand stopping Said counter circuit.

These and other featureacapabilities and ,-ad-

"vantages ofthe invention Willfappear .from the subjoined detaildescription of one embodiment and a modiiication thereof, illustrated inthe accompanying drawings, in which:

Fig. 1 is a 'block circuit diagram of a preferred form oisignal-transmitting apparatus according to the present invention; y

Fig. 2 is a partial detailed circuit diagram of some of the controlelements shown in block form in Fie. i;

Fig. .3 is a .circuit diagram, partially in block form, illustrating anintelligence receiving and converting system adapted to be used with thetransmitting system illustrated in Figs. 1 and 2;

Fig. 4 shows examples of intelligence `in the form of letters andnumerals of the type which will be reproduced by ythe system`illustrated in Figs. 1. 2 and; and

Fig. 5 is a partial detailed circuit diagram of aY modified form ofsignal-transmitting apparatus.

The general arrangement of ya preferred form of .intelligencedetermining and transmitting system according to the .present inventionis i1- lustrated in Fig. V1. Such .a system may include a suitablekeyboard :lo which itself may .be made of Well-known construction, the,keys of which will have indicia marked thereon vcorresponding to thecharacter of signal .to be transmitted. A sequence of timed pulses willbe obtained from tbeelectronic counter circuit l2 and, in accordancewith the particular :key depressedon the keyboard l0, these pulses -Willbe directed to actuate one rci the gate rtubes 22a, 22h, .230,2211,2.29I 221 and 22g, .there being seven `of these gate tubes if, forexample, the system isa seven band system. -Each of the gate `tubes isrespectively energized by oscillators 24a, 24e, 24o, 24d,.24e, .24Je and24g, operating at diierent .frequencies :f1 to f7 respectively. In thepreferred `form of system illustrated, the gate .tubes .22a to 22ginclusive Y are connected .throughacommon outputlead to control themodulation vof a vtfansmitter 25 supplied from. 4a `carrier source .28.vIn the case `of .a wire transmission system, as contrasted to a |4a to|4g inclusive, so interconnected one with the other, in a manner knownto the art that after the first tube |4a is fired it will energize thesecond tube |41) which, in turn, will extinguish the tube |4a andenergize the next tube |4c. A counter circuit of this type is disclosed,for example, in the U. S. patent to Shumard 2,146,862, issued February14, 1939. Thus, the tubes become conductive and non-conductivesequentially down the line until the last tube |4g is energized. Toextinguish the tube 14g, I provide an additional gaseous discharge tube|411l which becomes conductive after the tube |4g and which will thenextinguish the latter. The tube |471. will become extinguishedautomatically after a predetermined period of time through theresistance-capacitance network I6, connected between the cathode of thetube |411, and ground. Output leads |8a to |8g inclusive, arerespectively connected to the cathodes of the tubes |4a to |4ginclusive, and as the tubes become sequentially conductive, a pulse willappear on each output lead, the pulse on one output lead being timedwith respect to the pulse appearing on the output lead of the priortube. The electronic counter circuit may be started by providing a shortpulse on a grid of the first tube |4a. For this purpose a switch 30 maybe provided on each of the keyboard keys 38. When any key is depressedthe switch 30 is momentarily closed and, through leads 32 and 34 willmomentarily energize the grid of the tube |4a from a source 0f power 38.Other means for energizing the grid of a gaseous discharge tube andknown to the art may, of course be used.

For the purpose of illustrating the formation of character-identifyingsignals by means of the present invention, I have shown in Fig. 2 threekeys which, upon being depressed will transmit pulses of such acharacter as to form upon the screen of a cathode ray tube the letter E,the

numeral 2 and the letter "N. Each key 38 in addition to the electroniccounter circuit starting switch 30, may include a plurality of switchingmeans for interconnecting the outputs of the gaseous discharge tubes |4ato |49 inclusive to the control circuits of the gate tubes 22a to 22ginclusive. For example, if the key corresponding to the letter E isdepressed the counter circuit |2 is initiated into action by themomentary closure of the switch 30 and at the same time control circuitsare established through switches 48a, 48h, 40o, 48d, 40e, 40j and 48g.An example of Fig. 4 (A) shows that in the formation of the letter E acontinuous pulse, or continuous series of pulses over the entiretransmitting band is necessary to form the upper portion of the letterat frequency f1; for frequencies f2 and f3 a pulse need be sent onlyover the first period; for frequency f4 pulses are sent over the firstfour periods; at frequencies f5 and f6 pulses are again only sent duringthe first period, and for frequency f7 pulses are again transmittedduring the entire band. Thus, since the gate tube 22a provides a signalat frequency f1 this gate tube must be energized for the entire band.Accordingly, the switch 48a connects the outputs of every one of thegaseous discharge tubes to the grid of the gate tube 22a by completing acircuit between conductors 50 and 52. It will be seen that conductor 50is connected to conductors 54a, 54h, 54e, 54d, 54e, 54j and 54g throughcommon conductor 56. The conductors 54a to 54g inclusive arerespectively connected to the gaseous discharge tube output leads |8a to|89 through suitable isolating resistors or resistors banks 20a to 20ginclusive. Since the gate tube 22h at frequency f2, should operate onlyduring the first period, closure of the switch 40h energizes the grid ofgate tube 22h by completing a circuit between conductors 58 and 60, theconductor 58 being interconnected with an isolating resistor in the bank20a, of tube |4a through conductors 62 and 64a. Likewise the switch 40ecompletes a circuit between conductors 65 and 68, thereby connecting theenergized conductor 62 with the grid of gate tube 22c. Since the gatetube 22d is to operate at frequency f4 for periods 1 to 4 inclusive, theswitch 40d will complete a circuit between conductors 10 and 12 whichinterconnect the grid of the gate tube 22d to the outputs of the rstfour tubes of the counter circuit. It will be noted in this case thatthe conductor is connected to the common conductor 14 which, in turn,connects to conductors 16a, 1Gb, '|60 and 16d, attached throughisolating resistors to the respective output leads |8a, |817, |8c and|8d. Gate tubes 22a and 22j producing pulsed energy at frequencies f5and f6 are again required to be energized only during the period ofconduction of the first tube of the counter circuit. Thus, the closureof switch 40e interconnects the common conductor 62 of the rst gaseousdischarge tube through conductors 18 and 80 to the gate tubes of 22ewhile closure of switch 40j completes a circuit from common conductor 62through conductors 82 and 84 to the grid of tube 221. For the letterchosen, the gate tube 22g will operate over the entire band at frequencyf" as did gate tube 22a at frequency f1. Thus, closure of switch 40gcompletes a circuit from the common conductor 56 through conductors 86and 88 to the grid of gate tube f".

Similar switching means are used for other characters in a mannersimilar to that just described, the manner of arrangement of contactsvarying of course, upon the type of letter to be transmitted. Inconnection with the formation of numeral 2 as illustrated in Fig. 4 (B)the control circuits will differ considerably from those used in makingthe letter EJ For example, at frequency f1 the gate tube 22a will beenergized for periods 2 to 6 inclusive and the switch 42a will, upon itsclosure and through conductors 9S and 92 connect the outputs of tubes|8b to |8f inclusive on the grid of this gate tube through conductors90, 92, common conductor 94 and individual conductors 86h to 96e, theselatter conductors being isolated from other conductors going to the sameoutput leads through other resistors of the resistor banks 2Gb to 20e.In certain instances as for example, for frequency f2 for the numeral 2,the gate tube must be twice energized and de-energized, for example, itmust be energized during the first period, and again for the fifth,sixth and seventh periods. To effect such a control of the gate tube22h, closure of the switch 42h establishes two circuits to the commonconductor |00 through the conductors 98 and |02. The conductor 98 can beconnected to the common lead 62 which will be the same one as used, forexample, for energizing the gate tubes at frequencies f2, f3, f5 and f6in connection with the formation of the letter E. The second conductor|02, however, will be attached through common lead |04 to the individualleads |088, |06f, and |069 to the output leads |86, lf, and |89,respectively, through suitable isolating resistors in resistance banks20e, 20j, and 20g. Closure of switches 42C, 42d, 42e, 42f, 42g and 42h Jinclusive.

"Will effect the closure of :proper circuits for `the igat'e tubestzcto22ginclusive to form the desired pulses for the .remaining frequencies13 to f7 The various circuits 'may be traced in .the manner given above.For example, 4closure :of switch 132e establishes .energization -ofAthis tube from gaseous discharge tubes Nid and hic through output leadsltd and we, individual conductors Hdd and `Hde, common conductor ||2 andconductors -.|-U8 and |10; closure of switch Ilfd establishesenergieation'of gate tube 22d from -gas dischargetubes `Mc and Mdthroughfoutput leads lcand ltd, individual conductors |200 and 1206i,common .conductor .H3 and conductors Ilfi and ,11.8. Gate .tube 22e willzbe energized from gaseous discharge .tubes llib and idc through output'leads l8b and |80, individual conductors |2811` and |.28c, commonconductor |26 and conductors |22 and |24. The energization of gate tube22f .by the gaseous discharge tubes bia and 4b may be Ysimilarlytraced'from Aoutput -leads |8a and |31), individual conductors 135e and |3021,common conductor 34 and conductors `|3iland |32. Since the gate tube 22gat frequency f7 is energized over the entire band, closure of the switch'42g may, through conductors |38 `and |40 establish a circuit from thecommon conductor 5.6 for 'all o1" 'the gaseous discharge tubes to thegridof this :gate tube.

i The restablisl'iin'g vorf `circuits fto 'form the letter ..N need notbe examined 'in y.detail but can be closure of ith-e various vswitchesHic to 44g inclusi've, taken in connection with conductors |42,

le, |88, |90, |92, ldysisl, lrf," 198g, `2MB, '262 and 204. .Attentionisdirected-to ythe fact, however, .that -in the formation fof aycharacter such as the letter N," 'it may be necessary vto 'start .and.stop the gate 'tube three times as, :for :eX- ample, the gate -tube.22o at :frequency ,73. This merely requires `a still further contact onthe switch 44e .as will be readily :appa-rent iffromethe drawings.Similar .switches are fused at 4521 and 44e.

Since, in accordance with .the mannerfof transmitting the pulsedcharacter-determining ifeatures by .means .of .the circuits illustratedin Figs.

1 and.2,.eachfrequency-band maybe fcdepending upon .the form .of thecharacter) simultaneously energized vand simultaneously transmitted 'if'the .signalsare to .be converted into `visual intelligence by .means ofAa 'cathode ray tube, the -re ceiver must be .provided .with means :forcontrolling the scanning of Vsucha.tubezfor-thepurpose A of separatingthe signals on'zthe diiierent firequencies. .An .example `of anarrangement for receiving and convertingsuch signals into visualintelligence upon .thescreen ofacathoderay-tube is illustrated in Fis.3. This .system .forms .no

part of the present invention but isY covered .in `the copendingapplication'of Edmond M. Delo-V raine and Louis A. de Rosa, S. N.489,760 "filed June 5, 1943. This receiver includes a suitable "broadband receiving apparatus 268 having a "tuning circuit "Z'I'Btunable overthe range of fre- 6 iode .ray beam may :be `controlled `from .an'oscillator 12815 which through a 4clipper 288, a diierentiator '2&0.and :generator 292, supplies a sawt'ooth :Wave of, for example, 30cycles tothe hori- 'zontal lplates o'i the rcathode ray tube. Thediftferentiatorll `may valso key `a second oscillator .2394 controlling'assaw-tooth wave Agenerator `296 of, for example, V310,000 cyclesapplied to the vertilcal vbeam-scann-ing plates. These two `scanningAsources zwill, therefore, fcomb'ine 'to Amove the .beamfof the .cathoderay tube slowly across the fface A-of .the kscreen lbut rapidly up anddown. A phaser 29B Fmay 'be yused to control the oscillator 12&6 :sothat the picture .of the 4received character 'may =be properlypositioned ion the screen Vof the Vcathode naytube. The high frequencygenerator 2.8.6 mayalsobe :used to control a reactance tube .2.12connected 'across the tuned circuit V21|] for themuipose #of :scanningthis 'tuned circuit at a frequency #corresponding Yto the `frequency ofthe vertical scanning -wave Aof :the cathode ray tube. llhus, `wher-1signals on 'frequency bands fl yto f7 :are simultaneousiy received, thecircuit 210 will lbe :seguenti-ahy tuned #over ythis frequency vband at:an 4exft-merriely rapid rate corresponding to the verticalscanningfrequency of the cathode ray tube '2184. .Throughthe control tube 274and the trigger cincuit 276, the control grid 282 will only permit asignal on the screen when ra signal at Athe frequency which is ybeinginstantaneously `scanned being received. Thus, as the hori- -zontalscanning of .the cathode ray tube `moves relativelyrslowly across -thescreen, the .grid 2-82 will yproduce -on the screen -a pattern built up.of .a seriesof short partial-pulses Whose horizontal .position is.determined by the .low `frequency gen- -.eratcr .Sil .and lWhosevertical position lis detersimultaneously. This will be true, forexample,

if the signals are to be .reproduced upon a Inov- 'ing tape. `In such .acase it will be merely necessary to apply the output trom a broadhandrece'iver 'through corresponding filters, .ampliiiers and rectiierstoindividual relays operating pencils or other .marking devices. Such asystem is more :fully .disclosed .and described in the afore- Vdescribed Deloraine and .de Rosa cbpending application.

In the counter .circuit illustrated in Fig. 2, provision was made for.stopping the operation of circuit automatically, after one seriesoperation. It is possible that a mere single transmission of the signalwould be insucient to produce a ,proper image on .the .screen of acathode` ray tube. and for this reason it may be desirable to provideacounter circuit whereby each letter will be repeated .several times. Amodication of the coiniter circuit indicated at |.2 in Fig, 5 will besatisfactory jfor this purpose. .The .counter cir- 'c it itself, in thiscase, .is substantially identical Withfthat illustrated in Fig. 2 exceptthat here the last .tubefl'lih is connected .back .to the first .tubeMalin thesarne manner fas .each .tube is connected to .thenextsucceeding vtube .so that as a nesult, .when @nce-.energized thecircuit Will ncontinue =t0 .operate unless ,positive .-means areprovided for stopping it.

In order to control the starting and stopping of the counter circuitIl2', I have also shown in Fig. 5 modified switches 30' which are opeatedwhen any one of the character-forming keys is depressed. Upon depressionof any key, the switches 30 will interconnect the lead 2li] attached tothe grid resistor for tube Ma to ground. This connection is momentarybut is sufcient to reduce the negative bias on the grid of this firsttube to start the same operating and thus initiate the entire electroniccounter circuit. In the nal position of a key 38, the switch 3B closes asecond contact which connects the cathode of the last tube lllh and thegrid of the first tube MU, to ground through a condenser 296, viaconductor 208. The effect of this connection is to permit severalrotations of the counter circuit, during which time a potential isgradually built up on the condenser 206 which will nally be sulcient toextinguish the last tube Mh and simultaneously prevent the first tubeIda from firing. The rate at which this potential builds up can becontrolled as desired, but will preferably be such as to permitlseveral, (as ten) revolutions of the counter circuit before the same isstopped. Thus, each letter will be repeated several times and a clearpicture of the same on the screen of a cathode ray tube in the receiveris assured.

Certain details of construction which will be obvious to those skilledin this art have not been minutely described since they themselves arenot considered to form any part of the present invention. For example,the details of the keyboard l (l have not been illustrated. Thiskeyboard may embody the features of usual keyboards known to the art inwhich, for example, the depression of one key automatically releases akey already depressed so that special releasing means for each key arenot necessary. Of course, additional means will be provided forreleasing a depressed key without pressing some other character-formingkey. While I have illustrated in Figs. 2 and 5, the addition of separateswitch means for each key to start or start and stop the respectiveelectronic counter circuits, it will be understood that such a separateswitch may be in the form of a separately actuated key, if desired.Furthermore, while I have illustrated as an example of lthis invention akeyboard in which the keys directly operate switches for interconnectingthe output of the electronic counter circuits with the various gatetubes, it will be understood by those skilled in this art thatindividual keys may ectuate relays for accomplishing this indirectlyinstead of directly, The form of switch mechanism illustrated has onlybeen given by way of example and it is not intended thatl this inventionbe limited to any particular type of key-operated switch mechanism.

No means have been illustrated for definitely synchronizing the receiverwith the transmitter systems above described. Such synchronization isnot necessary in most cases and the mere adjustment of the scanningvoltage by a phaser as described to bring the picture of the characterto the center of the screen is usually sucient. However, if positivesynchronization is desired, this may be effected by the transmission andreception of an additional synchronizing pulse in the manner known tothe art. Such synchronizing pulse might, for example, be derived fromthe additional tube of the trigger circuit.

While I have shown and described one embodiment of the invention and onemodication thereof, it is to be understood that it may be embodied inother forms without departing from the principles thereof. Accordingly,it is to be understood that this description is made only by way ofexample and not as a limitation on the scope of my invention as setforth in the objects and the accompanying claims.

I claim:

l. In a system for the transmission and reception of intelligence, thecombination of an electronic counter circuit including a plurality ofsequentially firing gaseous discharge tubes, means deriving a series ofsequentially timed pulses from said gaseous discharge tubes, acorresponding plurality of normally non-conductive gate tubes, anactuating circuit for each gate tube, a separate energy source for eachgate tube, the frequency of each source being different, transmittingmeans connected to the outputs of said gate tubes, means for startingand stopping said electronic counter circuit. switching meansrespectively interconnecting the outputs of said gaseous discharge tubesto the actuating circuits of said gate tubes to apply the sequentiallytimed pulses thereto in accordance with the intelligence-signifyingsignals desired, and a receiver, said receiver including meansconverting the received pulsed signals into intelligence 2. Thecombination according to claim 1, in which said switching meanscomprises a keyboard lnrovided with a plurality of control keys eachhaving indicia thereon corresponding to a character to be transmitted,and switches intermediate the outputs of said gaseous discharge tubesand the actuating circuits of said gate tubes operated, by said keys. f

3. The combination according to claim l., in which said switching meanscomprises a keyboard provided with a pluralityr of control keys eachhaving indicia thereon corresponding to a character to be transmitted,and switches intermediate the outputs of said gaseous discharge tubesand the actuating circuits of said gate tubes, operated by said keys,and in which said starting means includes an additional switch actuatedby each key, connected to the grid circuit of the rst tube, and meanscontrolled by said additional switches tor momentarily increasing thegrid potential of said rst tube.

4. A system for producing intelligence-signifying signals comprising, incombination, an electronic counter circuit including a plurality ofsequentially firing gaseous discharge tubes, means deriving a series ofsequentially timed pulses from said gaseous discharge tubes, acorresponding plurality oi' normally non-conductive gate tubes and anactuating circuit for cach gate tube, a separate energy source for eachgate tube, the frequency of each source being different, transmittingmeans connected to the outputs of said gate tubes, means for startingand stopping said electronic counter circuit, and switching meansrespectively interconnecting the outputs of said gaseous discharge tubesto the actuating circuits of said gate tubes to apply the sequentiallytimed pulses thereto in accordance with the intelligence-signifyingsignals desired.

5. The combination according to claim 4, in which said switching meanscomprises a keyboard provided with a plurality of control keys eachhaving indicia thereon corresponding to a character to be transmitted,and switches intermediate the outputs of said gaseous discharge tubesand said gate tubes operated by said keys.

6. The combination according to claim 4, in which said switching meanscomprises a keyboard provided with a plurality of control keys eachhaving indicia thereon corresponding to a character to be transmitted,and switches intermedia-te the outputs of said gaseous discharge tubesand said gate tubes operated by said keys, and in which said startingmeans includes an additional switch actuated by each key, connected tothe grid circuit of the iirst tube, and means controlled by saidadditional switches for momentarily increasing the grid potential ofsaid rst tube.

7. The combination according to claim 4, in which the means for stoppingsaid electronic counter circuit comprises an additional gaseousdischarge tube for extinguishing the last tube of said counter circuit,and a condenser-resistor leakage circuit connected to the cathode ofsaid additional tube for extinguishing the same a prez determined timeafter it has been energized, and in which said starting circuit includesmeans for temporarily increasing the grid potential on the rst tube ofthe counter circuit.

8. I'he combination according to claim 4, in which said switching meanscomprises a keyboard provided with a plurality of control keys eachhaving indicia thereon corresponding to a character to be transmitted,and switches intermediate the outputs of said gaseous discharge tubesand said gate tubes, operated by said keys, in which said starting meansincludes an additional switch actuated by each key, connected to thegrid circuit of `the rst tube and means controlled by said additionalswitches for momentarily increasing the grid potential of said iirsttube, and in which said stopping means comprises an .additional gaseousdischarge tube for extinguishing the' last tube of said counter circuitand a condenser-resistor leakage circuit connected to the cathode ofsaid additional tube for extinguishing same a predetermined time afterit has been energized.

9. The combination according to claim 4, in combination with anadditional gaseous discludes a condenser and a ground, means connectingthe grid of the rst tube to the ground for reducing the grid biasthereon and render said rst tube conductive, and means for connectingthe grid of the lirst tube and cathode of said additional tube to groundthrough said condenser to build up sufficient potential on saidcondenser after a number of cycles of operation to extinguish saidadditional tube without reenergizing the grid of said first tube,whereby said counter circuit will cease to operate.

10. The combination according to claim 4, in combination with anadditional gaseousr discharge tube interconnecting the last tube of saidelectronic counter circuit with the first tube thereof, whereby saidcounter circuit will operate in a continuously rotating fashion, inwhich said switching means comprises a keyboard provided with aplurality of control keys each having indicia thereon corresponding to acharacter to be transmitted, and switches intermediate the outputs ofsaid gaseous discharge tubes and said gate tubes, and in which saidstarting and stopping means includes a condenser, a ground, a negativegrid bias on said rst tube, an additional switch operated by each key,and conductors interconnecting each of said additional switches to saidground, said condenser, and the grid of said I-lrst tube and the cathodeof said additional tube, so that when a key is depressed each switchfirst, momentarily connects the grid of said first tube to ground forremoving the grid bias therefrom to start the counter circuit operating,and then in the final depressed position each switch connects the gridof the first tube and the cathode of the" additional tube to groundthrough said condenser to cut oiT the additional tube without startingthe first tube after a number of cycles of operation of the countercircuit.

LOUIS A. DE ROSA.

